Electrical stimulation device for applying frequency and peak voltage having inverse relationship

ABSTRACT

A portable electrical stimulation device is disclosed. In one aspect, the device includes a pair of electrodes configured to be electrically coupled to a user and a wave generator configured to provide an electrical signal to the user via the pair of electrodes. The wave generator is further configured to generate the electrical signal at one of a plurality of levels. Each of the plurality of levels is defined by at least a frequency, a peak voltage, and a peak current. For each of the levels the frequency is in a range of about 50 Hz-about 500 Hz, the peak voltage is in a range of about 40 V-about 250 V, the peak current is in a range of about 25 mA-about 150 mA, and the frequency and the peak voltage have a generally inverse relationship.

RELATED APPLICATIONS

This application is a divisional of U.S. Non-Provisional applicationSer. No. 16/673,615, filed Nov. 4, 2019, which claims priority to andthe benefit of U.S. Provisional Application No. 62/769,997 filed on Nov.20, 2018 in the U.S. Patent and Trademark Office, the entire contents ofeach of which are incorporated herein by reference.

BACKGROUND Technological Field

The described technology generally relates to an electrical stimulationdevice, and in particular, to a unique electrotherapy technology forpreventive care, injury recovery, pain management and overall wellnessfor the sports, fitness, health and/or wellness industries.

Description of the Related Technology

Portable electrical stimulation devices can be used to provide relief toinflamed, sore muscles, joints, and related tissues. One example of sucha device is a transcutaneous electrical nerve stimulation (TENS) device.Portable electrical stimulation devices may generate a low voltageelectric current which can be applied to a user in order to treatcertain conditions, such as inflamed, sore muscles, joints, and relatedtissues. Many commercially available TENS devices are generallyineffective in that they provide at best temporary pain relief andfrequently cause some discomfort to patients and users while they arebeing treated.

SUMMARY

One inventive aspect is a portable electrical stimulation device,comprising: a pair of electrodes configured to be electrically coupledto a user; and a wave generator configured to provide an electricalsignal to the user via the pair of electrodes, wherein the wavegenerator is further configured to generate the electrical signal at oneof a plurality of levels, each of the plurality of levels defined by atleast a frequency, a peak voltage, and a peak current, and wherein foreach of the levels: the frequency is in a range of about 50 Hz-about 500Hz, the peak voltage is in a range of about 40 V-about 250 V, the peakcurrent is in a range of about 25 mA—about 150 mA, and the frequency andthe peak voltage have a generally inverse relationship.

In certain embodiments, the wave generator is further configured togenerate waves that have a strictly positive voltage.

In certain embodiments, the wave generator is further configured to:generate waves having a substantially equal positive pulse width, andadjust the frequency of each of the levels by altering a neutral pulsewidth of the waves.

In certain embodiments, the wave generator is further configured to:receive a command to transition from a first level to a second levelthat is different from the first level, gradually increase the peakvoltage of waves to the peak voltage associated with the second level inresponse to the received command.

In certain embodiments, the wave generator comprises a current limiterarranged in series with an output of the wave generator.

In certain embodiments, the current limiter comprises a resistiveelement and/or or a negative temperature coefficient (NTC) thermistor.

Another aspect is a portable electrical stimulation device, comprising:a pair of electrodes configured to be electrically coupled to a user;and a wave generator configured to provide an electrical signal to theuser via the pair of electrodes, wherein the wave generator is furtherconfigured to generate the electrical signal at one of a plurality oflevels, each of the plurality of levels defined by at least a frequency,a peak voltage, and a peak current, and wherein for each of the levels:the peak current is in a range of about 25 mA-about 150 mA, and thefrequency and the peak voltage have a generally inverse relationship.

Yet another aspect is a portable electrical stimulation device,comprising: a pair of electrodes configured to be electrically coupledto a user; and a wave generator configured to provide an electricalsignal to the user via the pair of electrodes, the wave generatorcomprising a current limiter arranged in series with an output of thewave generator, wherein the wave generator is further configured togenerate the electrical signal at one of a plurality of levels, each ofthe plurality of levels defined by at least a frequency, a peak voltage,and a peak current, and wherein for each of the levels: the frequency isin a range of about 50 Hz-about 500 Hz, and the peak voltage is in arange of about 40 V-about 250 V.

Still yet another aspect is a method of using a portable electricalstimulation device, comprising: placing a first electrode at a firstlocation of a user; placing a second electrode at a second location ofthe user; selecting one of a plurality of levels for an electricalsignal to be applied to the first and second electrodes via a wavegenerator, the wave generator configured to provide the electricalsignal to the user via the pair of electrodes, wherein each of theplurality of levels is defined by at least a frequency, a peak voltage,and a peak current, and wherein the frequency and the peak voltage havea generally inverse relationship; and moving at least one of the firstand second electrodes along a region of the user's skin while theelectrical signal is provided to the first and second electrodes.

In certain embodiments, the method further comprises placing a thirdelectrode and a fourth electrode on a third location of the userdifferent from the first and second locations, wherein the moving the atleast one of the first and second electrodes is performed while theelectrical signal is provided to the third and fourth electrodes. Incertain embodiments, the third location is feet of the user.

Another aspect is a method of using a portable electrical stimulationdevice, comprising: placing a first electrode at a first location of afirst user; placing a second electrode at a second location of a seconduser; and selecting one of a plurality of levels for an electricalsignal to be applied to the first and second electrodes via a wavegenerator, the wave generator configured to provide the electricalsignal to the first user and the second user via the pair of electrodes,wherein each of the plurality of levels is defined by at least afrequency, a peak voltage, and a peak current, wherein the frequency andthe peak voltage have a generally inverse relationship, and applying theelectrical signal, with the wave generator, to the first and secondelectrodes while the second user is performing a massage on the firstuser, thereby forming an electrical path between the first and secondelectrodes via direct contact between the first and second users.

Yet another aspect is an electrical stimulation device, comprising: awave generator configured to provide an electrical signal; and at leastone electrode configured to output a stimulation pulse based on theelectrical signal, wherein the wave generator is further configured togenerate the electrical signal at one of a plurality of levels, each ofthe plurality of levels defined by at least a frequency, a peak voltage,and a peak current, and wherein for each of the levels: the frequency isin a range of about 50 Hz-about 500 Hz, the peak voltage is in a rangeof about 40 V-about 250 V, the peak current is in a range of about 25mA-about 150 mA, and the frequency and the peak voltage have a generallyinverse relationship.

In certain embodiments, the electrical stimulation device is portable orstationary.

In certain embodiments, the wave generator is wiredly or wirelesslyconnected to the at least one electrode.

In certain embodiments, the at least one electrode comprises one or moresensors configured to sense a user's reaction in response to thestimulation pulse having a first intensity level being applied to theuser, and wherein the wave generator is configured to automaticallyadjust a level of the electrical signal to a second intensity leveldifferent from the first intensity level based on the sensed user'sreaction.

In certain embodiments, the wave generator is configured toautomatically adjust the level of the electrical signal to the secondintensity level less than the first intensity level in response to thesensed user's reaction indicating that the user is feeling discomfortwith the stimulation pulse having the first intensity level.

In certain embodiments, the at least one electrode comprises one or moresensors configured to sense a user's impedance in response to thestimulation pulse having a first intensity level being applied to theuser, and wherein the wave generator is configured to automaticallyadjust a level of the electrical signal to a second intensity leveldifferent from the first intensity level based on the sensed user'simpedance.

In certain embodiments, the wave generator is configured toautomatically adjust the level of the electrical signal to the secondintensity level greater than the first intensity level in response tothe one or more sensors sensing no reaction by the user with thestimulation pulse having the first intensity level for a predeterminedperiod of time.

In certain embodiments, the device further comprises a memory configuredto store information regarding a user and a user's reaction to intensitylevels.

In certain embodiments, the wave generator is configured to generate theelectrical signal based on the information stored on the memory.

In certain embodiments, the at least one electrode comprises: a filter;a high density sponge placed over the filter; a flexible conductivecontact placed over the high density sponge; a cover covering theflexible conductive contact; and an electrical wire connected to theflexible conductive contact.

In certain embodiments, the at least one electrode has one of thefollowing shapes: a circular shape and a square shape.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view illustrating an example portableelectrical stimulation device in accordance with aspects of thisdisclosure.

FIG. 1B is an example diagram illustrating how the portable electricalstimulation device of FIG. 1A can be connected to a user in accordancewith aspects of this disclosure.

FIG. 2 is a block diagram illustrating an example of the componentswhich can be included in the portable electrical stimulation device inaccordance with aspects of this disclosure.

FIGS. 3A, 3B, 3C, 3D, and 3E are example circuit diagrams implementingportions of the block diagram of FIG. 2 in accordance with aspects ofthis disclosure.

FIGS. 4A, 4B, 4C and 4D are views of example embodiments of theelectrodes illustrated in FIG. 1B in accordance with aspects of thisdisclosure.

FIG. 5A is an example graph illustrating the relationship between thepeak voltage and the frequency over a plurality of levels generated bythe portable electrical stimulation device in accordance with aspects ofthis disclosure.

FIGS. 5B and 5C are graphs illustrating example waveforms which may begenerated by the wave generator of the portable electrical stimulationdevice in accordance with aspects of this disclosure.

FIG. 5D is a graph illustrating additional example waveforms which maybe generated by the wave generator of the portable electricalstimulation device in accordance with aspects of this disclosure.

FIG. 6 is an example use-mode of the portable electrical stimulationdevice in accordance with aspects of this disclosure.

FIG. 7 is a flowchart illustrating a method of treating a user with theportable electrical stimulation device in accordance with some aspectsof this disclosure.

FIG. 8 is a flowchart illustrating a method of treating a user with theportable electrical stimulation device in accordance with other aspectsof this disclosure.

DETAILED DESCRIPTION

In the following description, for purposes of explanation, numerousspecific details are set forth in order to provide a thoroughunderstanding of the various embodiments. It will be evident, however,to one of ordinary skill in the art that the various embodiments may bepracticed without these specific details.

Overview of Portable Electrical Stimulation Device

As described in various example embodiments, a portable electricalstimulation device is described herein. Although the example embodimentsare described with respect to a portable electrical stimulation devicefor the purpose of convenience of description, the described technologycan be applied to a non-portable or stationary electrical stimulationdevice.

FIG. 1A is a perspective view illustrating an example portableelectrical stimulation device 100 in accordance with aspects of thisdisclosure. FIG. 1B is an example diagram illustrating how the portableelectrical stimulation device 100 of FIG. 1A can be connected to a user110 in accordance with aspects of this disclosure.

With reference to FIG. 1A, the portable electrical stimulation device100 can be embodied as a portable device comprising a user interface225, a stand 103, and one or more connection ports (not illustrated)configured to be connected to external components and/or devices. Theportable electrical stimulation device 100 shown in FIG. 1A is merely anexample, and can have different structures, shapes, and/or userinterfaces. Furthermore, certain components may be removed or others canbe added to the portable electrical stimulation device 100. For example,the stand 103 may be removed and/or the user interface 225 may havedifferent designs and/or arrangements of input touch pads/buttons. Theuser interface 225 may include an integrated touch LCD screen for userinterface. The LCD screen may additionally include color changing LEDindicators showing that the portable electrical stimulation device 100is in a certain intensity level among multiple different intensitylevels.

In some embodiments, the portable electrical stimulation device 100 maybe wiredly or wirelessly connected to a user's portable communicationdevice (not shown) such as a smartphone. In these embodiments, thesmartphone may download a program or an application relating to thefunction of the user interface 225 so that the user may control the userinterface via the smartphone.

As shown in FIG. 1B, the portable electrical stimulation device 100 canbe coupled to one or more electrodes 105 configured to be placed on auser 110. The connection between the portable electrical stimulationdevice 100 and the electrodes 105 can be wired or wireless. During use,the electrodes 105 may be placed such that each of the electrodes 105forms an electrical connection with the user's 110 skin. As describedbelow in more detail, in some embodiments, one of the electrodes 105 maybe stationary and the other electrode may be movable during use. Instill other embodiments, both of the electrodes 105 may be moveableduring use. In yet other embodiments, both of the electrodes 105 may befixed during use. Furthermore, one of the electrodes 105 may bepositioned in electrical contact with a first user's skin and the otherelectrode may be positioned on the skin of a second user who is treatingthe first user. In certain embodiments, the electrical conductivitybetween the user 110 and the electrodes 105 can be increased byproviding a conductive or lubricant cream (not shown) between one ormore of the electrodes 105 and the user's 110 skin. The conductive orlubricant cream can also provide user comfort during use.

The portable electrical stimulation device 100 can treat various targetareas of body, including, but not limited to, feet, ankles, knees,calves, thighs, hip, shoulders, shoulder blades, lower back, biceps,tendons, muscle, scapula, skin, neck or glutes. Furthermore, knowledgeof anatomy is not required for use by individual users, and the positionof the electrodes 105 may not be critical for effective treatment insome embodiments. Various embodiments are advantageous over the standardTENS device at least in that the positioning of electrodes on apatient's body is critical to the effectiveness of the standard TENSdevice.

FIG. 2 is a block diagram illustrating an example of the componentswhich can be included in the portable electrical stimulation device 100in accordance with aspects of this disclosure. For example, in theembodiment of FIG. 2 , the portable electrical stimulation device 100includes a microcontroller 205 (which in certain implementations, may beembodied as one or more microcontrollers), a memory 210, an electrodeinterface module 220, a graphical user interface 225, a biometric useridentification module 230, a universal serial bus (USB) port 235, a DCpower source management module 240, LEDs 245, a speaker and/ormicrophone 250, a wireless interface 255, and an analog/digital datacollection module 260. In certain embodiments, the portable electricalstimulation device 100 may include a voice activation module (notillustrated) which may be implemented as a separate module and/orimplemented via software running on the microcontroller 205 using themicrophone 250 as an input. FIG. 2 is merely an example of the portableelectrical stimulation device 100, and the portable electricalstimulation device 100 can have many different configurations. Forexample, one or more of the illustrated blocks may be omitted from theportable electrical stimulation device 100, one or more additionalblocks may be added to the portable electrical stimulation device 100,two or more blocks combined and/or one block can be separated intomultiple blocks.

The electrode interface module 220 includes an electrode feedback module221 and a wave generator 223. As described herein, the wave generator223 is configured to generate an electrical signal to be provided to theuser 110 via the electrodes 105. Accordingly, the electrode interfacemodule 220 may be configured to electrically connect the electrodes 105to the wave generator 223. In certain embodiments, the wave generator223 is further configured to generate the electrical signal at one of aplurality of levels. Each of the levels may be defined by one or more ofthe following parameters: a frequency, a peak voltage, wave shape, and acurrent. The electrode feedback module 221 may receive a feedback signalindicative of one or more of the parameters of the electrical signalprovided to the user 110.

FIGS. 3A, 3B, 3C, 3D, and 3E are example circuit diagrams implementingportions of the block diagram of the portable electrical stimulationdevice 100 of FIG. 2 in accordance with aspects of this disclosure. Thecircuit diagrams shown in FIGS. 3A-3E are merely examples, and othercircuit configurations can also be used. Furthermore, certain circuitcomponents may be removed or others can be added to the circuit diagramsshown in FIGS. 3A-3E. As shown in FIGS. 3A-3E, the portable electricalstimulation device 100 may include the USB port 235, the microcontroller205, a battery charger module 310, a regulator 315, a battery connector320, a programming/debugging port 325, a testing port 330, one or moretiming crystals 335, an expansion port 340, one or more LEDs 345, one ormore control switches 350, and an electrical output circuit 355.

Referring to FIGS. 3A and 3B, the USB port 235 may be configured toconnect to an external USB charger to provide power to the portableelectrical stimulation device 100. In certain embodiments, themicrocontroller 205 may be configured to communicate with externaldevices (e.g., a computer, mobile phone, another portable electricalstimulation device 100, a feedback device, etc.) via the USB port 235.Thus, certain lines from the USB port 235 may be electrically connectedto the microcontroller 205. The battery charger 310 may be configured tocharge a battery (not illustrated) connected to the battery connector320 when USB power is received from the USB port 235. Depending onwhether the portable electrical stimulation device 100 is powered fromthe USB port 235 or the battery, the regulator 315 may be configured tostep up and/or step down the voltage received from the USB port 235 orthe battery to a voltage used by other components of the portableelectrical stimulation device 100. In some embodiments, a series boostcircuit may be used to produce the regulator input when driven by asource lower than, for example, 3.3V. Other embodiments may use a lowdropout regulator that produces, for example, 3.3V when supplied with3.3V or more. Although not shown, the electrical stimulation device 100may also be powered by an electrical power outlet (e.g., 100V-240V)using a power AC-DC adapter, in addition to or instead of the USB port235. In certain embodiments, the regulator 315 can step down a 5 V powervoltage to 3.3 V used by certain components.

As shown in FIGS. 3C and 3D, the microcontroller 205 may be configuredto connect to other internal and/or external components via one or moreports 325, 330, and 340. These ports 325, 330, and 340 may be configuredto allow for reconfiguration of the microcontroller 205. In addition toproviding output via the graphical user interface 225, themicrocontroller 205 may be configured to provide output via the LEDs 345and receive control input via the control switches 350. Themicrocontroller 205 may also use input received from the timing crystals335 to generate control signals, such as a boost clock signal, used togenerate the electrical signal provided to the electrodes 105. It shouldbe appreciated that in certain embodiments, one or more of the ports325, 330, and 340, LEDs 345, switches 350, and timing crystals 335 maybe omitted and/or implemented using other components.

Referring to FIG. 3E, the electrical output circuit 355 may beconfigured to receive the boost clock signal BOOST_CLK and a pulse outsignal PULSE_OUT from the microcontroller 205 and output the electricalsignal to the electrodes 105 via a high electrode port 380 and a lowelectrode port 385. In certain embodiments, the electrical outputcircuit 355 may be configured as a boost converter to boost the signalprovided by the boost clock signal. The boost clock signal BOOST_CLK andthe pulse out signal PULSE_OUT may be generated by the microcontroller205 to control generation of the electrical signal provided to theelectrodes 105. The pulse out signal PULSE_OUT may be high duringgeneration and/or application of a therapy pulse to the electrodes 105.The boost clock signal BOOST_CLK may be cycled high and low duringactive therapy to generate the electrical signal having pulses at thedesired level. Both of the boost clock signal BOOST_CLK and the pulseout signal PULSE_OUT may be low when not providing electrical therapy.

For example, a transistor 360 (e.g., an MOS switch transistor) may beconfigured to be switched on so as to draw current from the power supplyrail Vcc through an inductor L2 when the boost clock signal BOOST_CLK ishigh. For example, the transistor 360 may be configured to sink currentto ground through the inductor L2 while the boost clock signal BOOST_CLKis high, and once the boost clock signal BOOST_CLK switched to low, theenergy from the inductor L2 may be transferred to one or more capacitors365 where the current is stored prior to being provided to the electrodeports 380 and 385. In some embodiments, the one or more capacitors 365may include one or more additional capacitors arranged in series and/orin parallel (e.g., capacitors C24A, C24B) to adjust the capacitance ofthe capacitors 365, thereby affecting the amount of energy which can bestored on the one or more capacitors 365, at a given voltage.

The microcontroller 205 can control the voltage generated on the line370 (also referred to as the VHV voltage) by adjusting the boost clocksignal. In certain embodiments, the boost clock signal may be a squarewave or a pulse wave (also referred to as a pulse train) adjustable bythe microcontroller 205. For example, the microcontroller 205 may beconfigured to adjust one or more of the following parameters of theboost clock signal: the duty cycle (e.g., via the positive pulse width),the number of pulses applied, a feedback signal (illustrated asVHV_DIV100 in FIG. 3E) provided to the microcontroller, frequency,positive pulse width, neutral pulse width, etc. Since the capacitor 365is coupled to the power supply rail Vcc via the inductor L2, the voltageapplied to the capacitor 365 may increase during a ramp up period afterthe transistor 360 is activated by the boost clock signal. Thus, alonger positive pulse width on the boost clock signal may result in ahigher voltage signal supplied to the capacitor 365.

The microcontroller 205 can generate a pulse wave that drives the gateof the transistor 360 whose drain is electrically connected to thesupply voltage VCC (e.g., which may be a 3.3V supply). Themicrocontroller 205 generated boost clock pulse wave can be used toswitch the input of the boost circuit to charge the capacitor 365 to adesired level. The boost clock may be then disabled and the energystored in the capacitor 365 may be used to create a therapy pulse. Theenergy stored in the capacitor 365 may be a function of the number ofboost clock cycles applied by the microcontroller 205 to the capacitor365. Thus, voltage regulation can be done by controlling the number ofboost clock cycles and the duty cycle of the boost clock through themicrocontroller 205. In other embodiments, the microcontroller 205 cangenerate electrical signals having a shape other than a square wave or apulse wave. For example, in certain embodiments the microcontroller 205can generate non-rectangular wave such as a sine wave, a triangularwave, etc.

The energy stored on capacitor 365 can be supplied to the electrodes 105(and thus to the user 110) via the electrode ports 380 and 385. Themicrocontroller 205 can control application of the energy stored on thecapacitor 365 to the electrode ports 380 and 385 via the pulse outsignal provided to a transistor 390. In addition, part of the electricalsignal received back from the user 110 through the low electrode port385 can be provided to the microcontroller 205 as a feedback signalIOUT_X10 (see the left side of the text “TO MICROCONTROLLER 205” in FIG.3E) used to measure the electrical signal. In certain embodiments, thefeedback signal IOUT_X10 is provided to the electrode feedback module221 and the analog/digital data collection module 260 before beingprovided to the microcontroller 205.

The electrical output circuit 355 may further include a current limitingcomponent 375 arranged in series with at least one of the electrodeports 380 and 385. In certain embodiments, the current limitingcomponent 375 is embodied as one or more resistive elements arranged inseries prior to the output to the electrodes 105, which function tolimit the amount of current output. In other embodiments, the currentlimiting component 375 can be made with other circuits such as negativetemperature coefficient (NTC) thermistors. The microcontroller 205 or anadditional processor (not shown) of the portable electrical stimulationdevice 100 can also limit the amount of current output by software. Thecurrent limiting elements may improve the safety of the portableelectrical stimulation device 100 and prevent the higher levels fromdelivering too much power to the user 110, which may be uncomfortable tothe user 110.

FIGS. 4A, 4B, 4C and 4D are views of example embodiments of theelectrodes illustrated in FIG. 1B in accordance with aspects of thisdisclosure. As shown in FIGS. 4A, 4B and 4C, the electrode 105 includesflexible conductive contact 405, a cover 410, an electrical wire 415, ahigh density sponge 420, and a cover 430. In some embodiments, the cover430 comprises a wet paper towel or “tea bag” filter, however, thedetailed description is not limited thereto. In certain embodiments, theflexible conductive contact 405 may be formed of a conductive graphiteand the cover 410 may be formed of silicone. A conductive cream 425 mayalso be applied to the cover 430 before the electrode 105 is attached tothe user's 110 skin. The conductive cream 425 may improve electricalconductivity between the electrodes 105 and the user's 110 skin and/orcan be used as lubricant cream that provides comfort to the use 110,particularly, when one of the electrodes 105 is moving. In embodimentswhere the electrodes 105 are attached to the user's 100 feet, the highdensity sponge 420 and the conductive cream 425 may be omitted from theelectrode 105. FIG. 4D illustrates an embodiment of the electrodes 105which can be used as foot pads without the high density sponge 420 andthe conductive cream 425. In FIG. 4D, reference numeral 415 representsan electrical wire. As shown in FIGS. 4A, 4B, 4C and 4D, the electrode105 may have one of the following shapes: a circular shape or a squareshape. However, the shape of the electrode 105 is not limited theretoand in other embodiments, the electrode 105 may have various othershapes (e.g., polygonal shapes).

In certain embodiments, at least one of the electrodes 105 may alsoinclude one or more sensors configured to sense biometric parameters ofthe user 110 before and/or during treatment. The sensors may sense auser's impedance, other body characteristic or physical reaction (e.g.,sudden movement or shaking) in response to a first intensity level dueto a higher intensity than expected by the user. The microcontroller 205may use the measured parameters to automatically adjust the level of thegenerated electrical signal based on a model of the user's 110 responseto the electrical signal. For example, the microcontroller 205 canautomatically adjust the intensity level to a second intensity levellower than the first intensity level. As another example, if the sensorssense no reaction (e.g., the measured reaction is less than a thresholdlevel) from a user who is receiving treatment in a first intensity levelfor a predetermined period of time, the microcontroller 205 canautomatically adjust the intensity level to a second intensity levelhigher than the first intensity level. The sensing and automaticintensity level adjustment can be user configurable, for example, withrespect to the length of the predetermined time and/or the intensitylevel to be changed from an initial intensity level. Furthermore, theuser configurable information and/or setting can be saved in the memory210 for future uses by specific individuals. In other embodiments, theuser configurable information and/or setting can be saved in a networksystem such as a cloud database or user's mobile terminal forcommunicating with the portable electrical stimulation device 100.

In certain embodiments, the microcontroller 205 can recognize a user'svoice command received through the microphone 250 (see FIG. 2 ) inconnection with operations of the portable electrical stimulation device100 such as turning on/turning off the device, timer duration, intensitylevel changes, etc. For example, if the user's voice command is tochange an intensity level from a first level to a second differentlevel, the microcontroller 205 can control the wave generator 223 tochange the intensity level from the first level to the second differentlevel.

Parameters of the Electrical Signal

In certain embodiments, the microcontroller 205 is configured togenerate the electrical signal at one of a plurality of intensitylevels. Each of the levels can be defined by parameters including atleast a frequency, a peak voltage, and/or a current. In certainembodiments, the microcontroller 205 may be configured to allow for theselection of one of five levels, having parameters defined by table 1below.

TABLE 1 Peak Active Output Voltage Pulse Frequency No Load Body LoadWidth Period Level (Hz) (V) (V) (ms) (ms) 1 328.5 92 56 2.000 3.044 2250.6 128 77 2.000 3.990 3 183.4 147 103 2.000 5.453 4 98.23 163 1472.000 10.18 5 60.13 210 156 2.000 16.63

The peak current for the above levels may vary between about 5 mA toabout 250 mA and may be determined based on the peak voltage Vmaxparameter and the current resistance of the user 110 between theelectrodes 105. The average current for the above levels may varybetween about 1 mA to about 15 mA. Thus, in certain embodiments, foreach of the levels: the frequency can be in a range of about 50 Hz toabout 500 Hz, the peak voltage can be in a range of about 40 V to about250 V, the peak current can be in a range of about 5 mA to about 250 mA.The frequency can also be in a range of about 60 Hz to about 400 Hz,about 70 Hz to about 350 Hz, or about 80 Hz to about 300 Hz, or anyother frequency ranges within the range of about 50 Hz to about 500 Hz.The peak voltage can be in a range of about 60 V to about 200 V, about70 V to about 180 V, or about 80 V to about 160 V, or any other voltageranges within the range of about 50 V to about 250 V. Additionally, thepeak voltage may vary according to the load presented to the wavegenerator 223 by the user 110 and/or if the electrodes 105 are notconnected to the user 110. The values illustrated in Table 1 may be anexample of the peak load measured for an example body load of a user110, which may vary depending on the user 110.

The peak current can be in a range of about 5 mA to about 250 mA, about10 mA to about 175 mA, about 25 mA to about 150 mA, or any other peakcurrent ranges within the range of about 5 mA to about 250 mA. Theaverage current can be in a range of about 1 mA to about 15 mA, about2.5 mA to about 7.5 mA, about 4 mA to about 6 mA, or any other peakcurrent ranges within the range of about 1 mA to about 15 mA.Additionally, the frequency and the peak voltage can have a generallyinverse relationship in which the peak voltage generally increases asthe level increases and the frequency generally decreases as the levelincreases, as shown in FIG. 5A. The intensity levels can be less or morethan five (e.g., three, seven, or any integer or other non-integervalue). Furthermore, the numbers shown in Table 1 are merely examplenumbers and can have different numbers as long as the frequency and thepeak voltage have a generally inverse relationship and/or the frequency,peak voltage and current satisfy the above described ranges.

Although not shown in Table 1, the root-means-square (RMS) voltage maybe relatively stable across the levels, and the overall power deliveredmay be limited (with a hard or soft cap) by the current limiting element375 or current limiting software described above. Additionally, incertain embodiments, the positive pulse width is static regardless ofthe levels when measured with an open circuit between the electrodes105. Accordingly, the microcontroller 205 may be configured to adjustthe neutral pulse width to achieve the frequency for the selected level.The microcontroller 205 may be configured to generate strictly positivepulses. In other embodiments, the microcontroller 205 may be configuredto generate waves having substantially equal active pulse widths (e.g.,at least one of the active pulse may not necessarily be positive) byaltering the period of the generated waves.

The user's 110 body may adapt to the electrical signals being applied bythe portable electrical stimulation device 100. Thus, it may bedesirable to adjust the level being applied during treatment. Theportable electrical stimulation device 100 may be configured to receivecontrol input to switch between the levels (e.g., a selection of one oflevels 1-5) via the control switches 350 or another user interface suchas graphical user interface 225 of microphone 250. While the portableelectrical stimulation device 100 switches between two levels, there maybe a short period of inactivity in which no electrical signal is appliedto the user 110. Thus, the user 110 may experience a “shock,” and/ordiscomfort if the full voltage of the newly selected level is appliedsubstantially instantaneously to the user 110. In certain embodiments,the portable electrical stimulation device 100 may be configured togradually increase the Vmax parameter when transitioning to the newlyselected level, to minimize such discomfort and/or shock from occurring.The portable electrical stimulation device 100 may generate thistransition by ramping and/or stepping the system up to the selectedlevel by applying parameters (e.g., the peak voltage Vmax) which arerepresented by sub-levels in between the above-indicated table oflevels.

FIGS. 5B and 5C are graphs illustrating example waveforms which may begenerated by the wave generator 223 of the portable electricalstimulation device 100 in accordance with aspects of this disclosure. Incertain embodiments, the waveforms 510 and 520 illustrated in FIGS. 5Band 5C may correspond to the electrical signal output to the electrodes105. Although the waveforms 510 and 520 are illustrated as pulse wavesin FIGS. 5B and 5C, aspects of this disclosure are not limited thereto.For example, the specific waveform applied to the user 110 may depend onthe load presented to the electrodes 105 when connected to the user 110,which may depend on, for example, the resistance of the user 110 duringapplication of the electrical signal, the placement of the electrodes105 on the user 110, and/or whether the conductive cream 425 is used,etc.

As shown in FIGS. 5B and 5C, each of the waveforms 510 and 520 generatedby the portable electrical stimulation device 100 may have substantiallythe same positive pulse width. Thus, in order to adjust the frequencybetween the waveform 510 and the waveform 520, the portable electricalstimulation device 100 may adjust the neutral pulse width. Although theterm neutral pulse width may be used to describe the period in which apositive pulse is not applied to the electrodes 105, the portableelectrical stimulation device 100 may provide an electrical signalhaving a voltage of about 0 V, rather than a strictly negative pulse.Although not specifically illustrated, the portable electricalstimulation device 100 may adjust the voltage of the neutral pulse widthaccording to the selected level in addition to adjusting the neutralpulse width to set the frequency.

FIG. 5D is a graph illustrating additional example waveforms 530-570which may be generated by the wave generator 223 of the portableelectrical stimulation device 100 in accordance with aspects of thisdisclosure. In particular, FIG. 5D illustrates an example waveform 530produced at level 1, an example waveform 540 produced at level 2, anexample waveform 550 produced at level 3, an example waveform 560produced at level 4, and an example waveform 570 produced at level 5,when the electrical signal is applied to the user 110 acting as a load.In certain embodiments, the load presented by the user 110 may be in therange of about 0.5 kΩ to about 6 kΩ, or, in the range of about 3 kΩ toabout 4 kΩ. Of course, the load presented by the user 110 may not bestrictly resistive and may include a capacitive component forming animpedance value.

As shown in FIG. 5D, the waveforms 530-570 may quickly approach a peakvalue as the capacitor 365 is unloaded through the electrodes 105. Foran example load of 2.2 kΩ, the electrical circuit formed between theportable electrical stimulation device 100 and the user 110 may have anIR time constant of about 0.3 ns and an RC time constant of about 1.3μs. The capacitor 365, the capacitance of the user 110, along with anyother sources of parasitic capacitance and/or inductance result in aramp up of the waveforms 530-570 to the peak value, within about 1 μs toabout 20 μs, depending on the level being produced by the portableelectrical stimulation device 100. In other embodiments, the ramp up ofthe waveforms 530-570 to the peak value may be less than about 1 μs orgreater than about 20 μs. The amount of time required to reach the peakvoltage value may increase with increasing level. As shown in FIG. 5D,the voltage of the waveforms 530-570 drop off from the peak value anddecay as the energy stored in the capacitor 365 is applied to the user110 through the electrodes 105.

Use Modes

The portable electrical stimulation device 100 may be used in aplurality of different use modes. FIG. 1B illustrates a certainembodiment of use modes in which two electrodes 105 are applied to theskin of the user 110. In a first use mode, the electrodes 105 may beplaced in stationary positions on the user 110 throughout a session ofuse of the portable electrical stimulation device 100. In a second usemode, a first one of the electrode 105 may be placed in a stationaryposition while the user 110 or another user moves a second one of theelectrode 105 over a region of the user's 110 body. In certainembodiments, the user 110 may place the electrodes 105 on their body.Since cream can be applied to the electrodes 105, it may not bedesirable for the user 110 to touch the portable electrical stimulationdevice 100 to adjust the currently applied level of the electricalsignal being generated by the portable electrical stimulation device100. As described above, the portable electrical stimulation device 100may include the microphone 250 and voice recognition system (e.g., whichmay be implemented by the microcontroller 205) which can be configuredto receive voice commands from the user 110 to operate the portableelectrical stimulation device 100. Accordingly, the user 110 may be ableto adjust the level of the portable electrical stimulation device 100,or input other commands to the portable electrical stimulation device100, while the user 110 is positioning the electrodes 105.

FIG. 6 is an example use-mode 600 of the portable electrical stimulationdevice 100 in accordance with aspects of this disclosure. In the usemode 600 illustrated in FIG. 6 , a first one of the electrodes 105 maybe placed on a first user 110 (e.g., a patient) while a second one ofthe electrodes 105 may be placed on a second user 610 (e.g., physicaltherapist, massage therapist, chiropractor or other healthcare provider(either professional or non-professional)). The portable electricalstimulation device 100 may be attached, held, or otherwise coupled tothe second user 610 via a strap 605 or another capability (e.g., belt,Velcro, etc.) for attaching the portable electrical stimulation device100 to the second user 610. However, in other embodiments, the portableelectrical stimulation device 100 may be placed on a surface (e.g., atable, the floor, etc.) with the second electrode 105 electricallycoupled to the second user 610 via the longer electrical wire 415. Thesecond user 610 may complete an electrical loop between the first andsecond electrodes 105 using their hands by applying their hands directlyto the skin of the first user 110. In certain embodiments, theelectrical connection between the second user's 610 hands and the firstuser 110 can be improved by using a conductive cream 425 and/or anotherconductive massage oil. In the use mode of FIG. 6 , the electricalstimulation provided by the portable electrical stimulation device 100via the second user's 610 hands can be combined with the effects ofphysical therapy (e.g., via a massage) to combine the effects of the twotherapies. In addition to the additive effects of the two therapies onthe first user 110, the electrical stimulation through the second user's610 hands can reduce the strain typically associated with performing amassage on the first user 110, thereby easing the burden of performingthe massage.

FIG. 7 is a flowchart illustrating a method 700 of treating a user withthe portable electrical stimulation device 100 in accordance with someaspects of this disclosure. The method 700 may involve a use-mode inwhich at least one of the electrodes is moved along a region of theuser's skin. The method 700 begins at block 701. At block 705, themethod 700 involves placing a first electrode 105 at a first location ofa user 110. At block 710, the method 700 involves placing a secondelectrode 105 at a second location of the user 110. At block 715, themethod 700 involves selecting one of a plurality of levels for anelectrical signal to be applied to the first and second electrodes 105via a wave generator 223. The wave generator 223 is configured toprovide the electrical signal to the user 110 via the pair of electrodes105. The levels are defined by at least a frequency, a peak voltage, anda current.

Depending on the embodiment, the user may provide input of the selectedlevel to one or more input devices (e.g., switches 350) formed on theportable electrical stimulation device 100 and/or via voice commandsreceived at a microphone 250 of the portable electrical stimulationdevice 100.

At block 720, the method 700 involves moving at least one of the firstand second electrodes 105 along a region of the user's 110 skin whilethe electrical signal is provided to the first and second electrodes105. In certain embodiments, the region may correspond to a region forwhich the user 110 desires treatment (e.g., a sore region and/or apainful region). Thus, the electrical signal may be applied to thedesired region. Optionally, the method 700 may involve moving the atleast one of the first and second electrodes along a sub-portion of theregion in which the user 110 determines most effective in treatment ofthe region. The method 700 ends at block 725.

FIG. 8 is a flowchart illustrating a method 800 of treating a user withthe portable electrical stimulation device 100 in accordance with otheraspects of this disclosure. The method 800 may involve a use-mode inwhich a second user performs a massage on a first user with assistancefrom the portable electrical stimulation device 100. The method 800begins at block 801. At block 805, the method 800 involves placing afirst electrode 105 at a first location of a first user 110.

At block 810, the method 800 involves placing a second electrode 105 ata second location of a second user 610. At block 815, the method 800involves selecting one of a plurality of levels for an electrical signalto be applied to the first and second electrodes 105 via a wavegenerator 223.

The wave generator is configured to provide the electrical signal to thefirst user 110 via the pair of electrodes 105 and the second user 610.The levels are defined by at least a frequency, a peak voltage, and/or acurrent. The wave generator 223 is further configured to apply theelectrical signal to the first and second electrodes 105 while thesecond user 610 is performing a massage on the first user 110, therebyforming an electrical path between the first and second electrodes 105via direct contact between the first and second users 110 and 610. Themethod 800 ends at block 820.

One or more of the above-described aspects of this disclosure may resultin certain advantages over other typical TENS devices. For example, theportable electrical stimulation device 100 may provide therapy formusculoskeletal challenges involving pain, inflammation, stiffness andother related body ailments via the delivery of microcurrent wavesresonating with those at healthy levels of the body. The portableelectrical stimulation device 100 may mimic the principles ofacupuncture and western/eastern medicine and replicates many of thebenefits of a deep tissue massage without discomfort. For example, thedescribed technology can provide improvements in body health. Suchimprovements can include, but are not limited to, one or more of: i)reducing or eliminating pain, ii) reducing swelling, iii) stimulatingand relaxing muscles and stimulating muscle tone, iv) increasingelasticity of tendons and ligaments, v) increasing patients range ofmotion and mobility, vi) improving circulation and blood flow throughoutbody and vii) assisting after training recovery and promoting theremoval of toxins or lactic acids.

The described technology can also provide healing and recovery benefits.Such benefits can include, but are not limited to, one or more of: i)aiding in the treatment of various injury types, sports and everydayliving, ii) promoting tissue healing and connective tissue repair andrebuilding, iii) reducing tension in muscles, tendons and relaxing bodyfor better sleep and iv) assisting in pre and post surgery bystrengthening muscle, increasing blood flow, and removal ofinflammation.

The described technology can also provide improvements in preventativebenefits. Such benefits can include, but are not limited to, one or moreof: i) pre-warming up to loosen muscles and tendons, thereby helpingprevent injury, ii) increasing flexibility and strength during warm-upand boosting body's natural energy, iii) loosening muscles and tendonsand increasing blood and energy flow throughout the body, iv) reducinginflammation across body mass improving flexibility and performance andv) enhancing physiologic change at cellular level creating balance atall levels of the body.

Other Variations

The foregoing description details certain embodiments of the systems,devices, and methods disclosed herein. It will be appreciated, however,that no matter how detailed the foregoing appears in text, the systems,devices, and methods can be practiced in many ways. The use ofparticular terminology when describing certain features or aspects ofthe disclosure should not be taken to imply that the terminology isbeing redefined herein to be restricted to including any specificcharacteristics of the features or aspects of the technology with whichthat terminology is associated.

It will be appreciated by those skilled in the art that variousmodifications and changes can be made without departing from the scopeof the described technology. Such modifications and changes are intendedto fall within the scope of the embodiments. It will also be appreciatedby those of skill in the art that parts included in one embodiment areinterchangeable with other embodiments; one or more parts from adepicted embodiment can be included with other depicted embodiments inany combination. For example, any of the various components describedherein and/or depicted in the figures can be combined, interchanged, orexcluded from other embodiments.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art can translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations can be expressly set forth herein for sakeof clarity.

Directional terms used herein (for example, top, bottom, side, up, down,inward, outward, etc.) are generally used with reference to theorientation or perspective shown in the figures and are not intended tobe limiting. For example, positioning “above” described herein can referto positioning below or on one of sides. Thus, features described asbeing “above” may be included below, on one of sides, or the like.

It will be understood by those within the art that, in general, termsused herein are generally intended as “open” terms (for example, theterm “including” should be interpreted as “including but not limitedto,” the term “having” should be interpreted as “having at least,” theterm “includes” should be interpreted as “includes but is not limitedto,” etc.). It will be further understood by those within the art thatif a specific number of an introduced claim recitation is intended, suchan intent will be explicitly recited in the claim, and in the absence ofsuch recitation no such intent is present. For example, as an aid tounderstanding, the following appended claims can contain usage of theintroductory phrases “at least one” and “one or more” to introduce claimrecitations. However, the use of such phrases should not be construed toimply that the introduction of a claim recitation by the indefinitearticles “a” or “an” limits any particular claim containing suchintroduced claim recitation to embodiments containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (for example, “a” and/or “an” should typically be interpreted tomean “at least one” or “one or more”); the same holds true for the useof definite articles used to introduce claim recitations. In addition,even if a specific number of an introduced claim recitation isexplicitly recited, those skilled in the art will recognize that suchrecitation should typically be interpreted to mean at least the recitednumber (for example, the bare recitation of “two recitations,” withoutother modifiers, typically means at least two recitations, or two ormore recitations).

The term “comprising” as used herein is synonymous with “including,”“containing,” or “characterized by,” and is inclusive or open-ended anddoes not exclude additional, unrecited elements or method steps.

Conditional language, such as “can,” “could,” “might,” or “may,” unlessspecifically stated otherwise, or otherwise understood within thecontext as used, is generally intended to convey that certainembodiments include, while other embodiments do not include, certainfeatures, elements, and/or steps. Thus, such conditional language is notgenerally intended to imply that features, elements, and/or steps are inany way required for one or more embodiments or that one or moreembodiments necessarily include logic for deciding, with or without userinput or prompting, whether these features, elements, and/or steps areincluded or are to be performed in any particular embodiment.

Language of degree used herein, such as the terms “approximately,”“about,” “generally,” and “substantially” as used herein represent avalue, amount, or characteristic close to the stated value, amount, orcharacteristic that still performs a desired function and/or achieves adesired result. For example, the terms “approximately”, “about”,“generally,” and “substantially” may refer to an amount that is withinless than 10% of, within less than 5% of, within less than 1% of, withinless than 0.1% of, and/or within less than 0.01% of the stated amount.

It will be further understood by those within the art that anydisjunctive word and/or phrase presenting two or more alternative terms,whether in the description, claims, or drawings, can be understood tocontemplate the possibilities of including one of the terms, either ofthe terms, or both terms. For example, the phrase “A or B” will beunderstood to include the possibilities of “A” or “B” or “A and B.”Further, the term “each,” as used herein, in addition to having itsordinary meaning, can mean any subset of a set of elements to which theterm “each” is applied.

Conjunctive language such as the phrase “at least one of X, Y, and Z,”unless specifically stated otherwise, is otherwise understood with thecontext as used in general to convey that an item, term, etc. may beeither X, Y, or Z. Thus, such conjunctive language is not generallyintended to imply that certain embodiments require the presence of atleast one of X, at least one of Y, and at least one of Z.

The various illustrative logical blocks, modules, circuits, andalgorithm steps described in connection with the embodiments disclosedherein may be implemented as electronic hardware, computer software, orcombinations of both. To clearly illustrate this interchangeability ofhardware and software, various illustrative components, blocks, modules,circuits, and steps have been described above generally in terms oftheir functionality. Whether such functionality is implemented ashardware or software depends upon the particular application and designconstraints imposed on the overall system. The described functionalitymay be implemented in varying ways for each particular application, butsuch implementation decisions should not be interpreted as causing adeparture from the scope of the embodiments of the invention.

The various illustrative blocks, modules, and circuits described inconnection with the embodiments disclosed herein may be implemented orperformed with a general purpose processor, a Digital Signal Processor(DSP), an Application Specific Integrated Circuit (ASIC), a FieldProgrammable Gate Array (FPGA) or other programmable logic device,discrete gate or transistor logic, discrete hardware components, or anycombination thereof designed to perform the functions described herein.A general purpose processor may be a microprocessor, but in thealternative, the processor may be any conventional processor,controller, microcontroller, or state machine. A processor may also beimplemented as a combination of computing devices, e.g., a combinationof a DSP and a microprocessor, a plurality of microprocessors, one ormore microprocessors in conjunction with a DSP core, or any other suchconfiguration.

The steps of a method or algorithm and functions described in connectionwith the embodiments disclosed herein may be embodied directly inhardware, in a software module executed by a processor, or in acombination of the two. If implemented in software, the functions may bestored on or transmitted over as one or more instructions or code on atangible, non-transitory computer-readable medium. A software module mayreside in Random Access Memory (RAM), flash memory, Read Only Memory(ROM), Electrically Programmable ROM (EPROM), Electrically ErasableProgrammable ROM (EEPROM), registers, hard disk, a removable disk, a CDROM, or any other form of storage medium known in the art. A storagemedium is coupled to the processor such that the processor can readinformation from, and write information to, the storage medium. In thealternative, the storage medium may be integral to the processor. Diskand disc, as used herein, includes compact disc (CD), laser disc,optical disc, digital versatile disc (DVD), floppy disk and blu ray discwhere disks usually reproduce data magnetically, while discs reproducedata optically with lasers. Combinations of the above should also beincluded within the scope of computer readable media. The processor andthe storage medium may reside in an ASIC. The ASIC may reside in a userterminal. In the alternative, the processor and the storage medium mayreside as discrete components in a user terminal.

The above description discloses embodiments of systems, apparatuses,devices, methods, and materials of the present disclosure. Thisdisclosure is susceptible to modifications in the components, parts,elements, steps, and materials, as well as alterations in thefabrication methods and equipment. Such modifications will becomeapparent to those skilled in the art from a consideration of thisdisclosure or practice of the disclosure. Consequently, it is notintended that the disclosure be limited to the specific embodimentsdisclosed herein, but that it cover all modifications and alternativescoming within the scope and spirit of the subject matter embodied in thefollowing claims.

1. A method of using a portable electrical stimulation device,comprising: placing a first electrode at a first location of a user;placing a second electrode at a second location of the user; selectingone of a plurality of levels for an electrical signal to be applied tothe first and second electrodes via a wave generator, the wave generatorconfigured to provide the electrical signal to the user via the firstand second electrodes, wherein each of the plurality of levels isdefined by at least a frequency, a peak voltage, and a peak current, andwherein the frequency and the peak voltage have a generally inverserelationship; and moving at least one of the first and second electrodesalong a region of the user's skin while the electrical signal isprovided to the first and second electrodes.
 2. The method of claim 1,further comprising: placing a third electrode and a fourth electrode ona third location of the user different from the first and secondlocations, wherein the moving the at least one of the first and secondelectrodes is performed while the electrical signal is provided to thethird and fourth electrodes.
 3. The method of claim 2, wherein the thirdlocation is feet of the user.
 4. A method of using a portable electricalstimulation device, comprising: placing a first electrode at a firstlocation of a first user; placing a second electrode at a secondlocation of a second user; selecting one of a plurality of levels for anelectrical signal to be applied to the first and second electrodes via awave generator, the wave generator configured to provide the electricalsignal to the first user and the second user via the first and secondelectrodes, wherein each of the plurality of levels is defined by atleast a frequency, a peak voltage, and a peak current, wherein thefrequency and the peak voltage have a generally inverse relationship;and applying the electrical signal, with the wave generator, to thefirst and second electrodes while the second user is performing amassage on the first user, thereby forming an electrical path betweenthe first and second electrodes via direct contact between the first andsecond users.
 5. The method of claim 1, wherein the wave generatorcomprises a current limiter disposed outside of the first electrode andthe second electrode.
 6. The method of claim 5, wherein the currentlimiter comprises a resistive element.
 7. The method of claim 5, whereinthe wave generator comprises an output terminal, and wherein the currentlimiter is arranged in series with the output terminal of the wavegenerator.
 8. The method of claim 1, further comprising: generating,using the wave generator, waves having a substantially equal positivepulse width; and adjusting, using the wave generator, the frequency ofeach of the levels by altering a neutral pulse width of the waves whilemaintaining the positive pulse width.
 9. The method of claim 1, furthercomprising: storing, in a memory, user information comprising anidentification of the user and the user's previous reaction to theplurality of levels; sensing, by one or more sensors of the portableelectrical stimulation device, biometric parameters of the user;identifying, by a biometric user identification module of the portableelectrical stimulation device, the user based on the sensed biometricparameters of the user; retrieving the user information of theidentified user from the memory; automatically selecting a signal levelof the plurality of levels based on the retrieved user information; andapplying the selected signal level to the user via the first and secondelectrodes.
 10. The method of claim 1, further comprising: generating,using the wave generator, waves having a strictly positive voltage. 11.The method of claim 1, wherein each of the plurality of levels isdefined by one or more of 1) a frequency in a range of about 50 Hz-about500 Hz, 2) a peak voltage in a range of about 40 V-about 250 V, or 3) apeak current in a range of about 25 mA-about 150 mA.
 12. The method ofclaim 1, wherein the wave generator comprises: a microcontrollerconfigured to generate a boost clock signal and a pulse out signal, aboost converter configured to receive the boost clock signal andgenerate a boosted signal, and at least one transistor configured togenerate the electrical signal based on the pulse out signal and theboosted signal.
 13. The method of claim 1, further comprising:instructing the wave generator to transition from a first level to asecond level that is different from the first level; and graduallyincreasing, using the wave generator, the peak voltage of the firstlevel to a peak voltage of the second level in response to instructingthe wave generator to transition from the first level to the secondlevel.
 14. The method of claim 4, wherein the wave generator comprises acurrent limiter disposed outside of the first electrode and the secondelectrode.
 15. The method of claim 14, wherein the current limitercomprises a resistive element.
 16. The method of claim 14, wherein thewave generator comprises an output terminal, and wherein the currentlimiter is arranged in series with the output terminal of the wavegenerator.
 17. The method of claim 4, further comprising: generating,using the wave generator, waves having a substantially equal positivepulse width; and adjusting, using the wave generator, the frequency ofeach of the levels by altering a neutral pulse width of the waves whilemaintaining the positive pulse width.
 18. The method of claim 4, furthercomprising: storing, in a memory, user information comprising anidentification of the first user and the first user's previous reactionto the plurality of levels; sensing, by one or more sensors of theportable electrical stimulation device, biometric parameters of thefirst user; and identifying, by a biometric user identification moduleof the portable electrical stimulation device, the first user based onthe sensed biometric parameters of the first user; retrieving the firstuser information of the identified first user from the memory;automatically selecting a signal level of the plurality of levels basedon the retrieved first user information; and applying the selectedsignal level to the first and second electrodes.
 19. The method of claim4, further comprising: generating, using the wave generator, waveshaving a strictly positive voltage.
 20. The method of claim 4, whereineach of the plurality of levels is defined by one or more of 1) afrequency in a range of about 50 Hz-about 500 Hz, 2) a peak voltage in arange of about 40 V-about 250 V, or 3) a peak current in a range ofabout 25 mA-about 150 mA.